Facile synthesis of new sodium alginate–anthracene based photosensitizers

Facile syntheses of water-soluble sodium alginate (Na-Alg) derivatives employing anthracene moieties (Anth) have been carried out. Na-Alg amide (Alg-Anth amide), and Na-alg ester (Alg-Anth ester) derivatives were synthesized using 2-amino anthracene and 9-chloromethyl anthracene (9-CMA), respectively. These polymeric materials were characterized (FTIR, 13 C NMR, GPC, UV–Vis and fluorescence spectroscopy). These derivatives were photoactive and demonstrated photosensitizing capabilities in presence of an acceptor pyrene. Alg-Anth ester was more efficient (63 %) as opposed to Alg-Anth amide (37 %) in transferring energy to the acceptor. Further hydrophilic–lipophilic balance (HLB) values (>10.0) of both the derivatives indicated their suitability as solubilizers. These water-soluble polysaccharide-based polymers may be of potential utility as photosensitizers for reactions of organic compounds in aqueous media as well as in sensory applications.